1. Field of the Invention
The present invention relates to a resin binder composition for a non-contact fixing process used for developing electrostatic latent images formed in electrophotography, electrostatic recording method, electrostatic printing, and the like, a toner for a non-contact fixing process comprising the resin binder composition, a developer comprising the toner for a non-contact fixing process, and a method for fixing the toner in a non-contact fixing process.
2. Discussion of the Related Art
A non-contact fixing process includes a process in which light or heat energy is applied to a toner in a non-contacting state, thereby fixing the toner, such as a flash fixing or radiant (oven) fixing process, which has a feature in that the offset phenomenon and the deterioration of resolution, which are often found in contact-fixing, are not found. However, when the light or heat energy is deficient during fixing, the toner cannot be sufficiently melted, so that satisfactory fixing ability cannot be obtained. On the other hand, when the light or heat energy is too intensive, the viscosity of the toner drastically is lowered. When the surface tension acting on the toner exceeds the viscosity, the aggregation and migration of the toner at printed portion take place, so that there is generated a so-called xe2x80x9cvoids,xe2x80x9d which are white voids phenomenon on a fixed image, whereby the photographic density of the image is lowered. Therefore, toners using a specific resin binder are disclosed in Japanese Patent Laid-Open Nos. Hei 8-87130, Hei 5-107805, and the like, in view of eliminating these defects found in the non-contacting fixing process. However, further improvements in the environmental resistance and the storage ability are desired, even though the fixing ability and the void resistance are somewhat improved.
An object of the present invention is to provide a resin binder composition for a non-contact fixing process which suppresses unpleasant odor generated during non-contact fixing process, and is excellent in the fixing ability and the void resistance.
Another object of the present invention is to provide a toner for a non-contacting fixing process comprising the resin binder composition, and a developer comprising the toner for a non-contacting fixing process.
Still another object of the present invention is to provide a method for fixing the toner in a non-contact fixing process.
These objects and other objects of the present invention will be apparent from the following description.
The present invention pertains to the following:
[1] a resin binder composition for a non-contact fixing process comprising two or more polyesters having different softening points, wherein the polyesters comprise at least one polyester having a softening point of 80xc2x0 C. or more and less than 120xc2x0 C. (low-softening point polyester), and at least one polyester having a softening point of 120xc2x0 C. or more and 160xc2x0 C. or less (high-softening point polyester), wherein each of the polyesters is obtained from a carboxylic acid component consisting essentially of an aromatic carboxylic acid compound, and wherein the high-softening point polyester is a cross-linked polyester;
[2] a toner for a non-contact fixing process comprising the resin binder composition as defined above;
[3] a developer comprising the toner as defined above; and
[4] a method for fixing a toner in a non-contact fixing process, comprising applying the toner to a fixing device, wherein the toner comprises the resin binder composition defined above.